The outcome of the civil war in Syria is bound to test the balance of forces in the Levant, and further afield too. The United States has enemies in Iran and Hezbollah and vulnerable allies in Israel and Jordan. The predicament has evidently been too much for President Obama, and instead of a coherent policy he has so far come up with words alone. Among those words was a warning to Bashar Assad not to resort to poison gas. To do so, the president declared, would be to cross a red line, or in the other thumping cliché of realpolitik, a game-changer. There are precedents. Intervening in the Yemeni civil war, Egyptian president Gamal Abdul Nasser had used poison gas, and Saddam Hussein devastated his Kurdish population that way. Assad is another despot who will stop at nothing.

Well, Assad has crossed the red line and changed the game. Sarin is a nerve gas with unmistakable symptoms, and victims showing those symptoms and dying from them have been named and photographed. British intelligence confirms their death through gas, and so does Israeli military intelligence. Secretary of Defense Chuck Hagel has a response, “We still have some uncertainties about what was used.” An official spokesman has “varying degrees of confidence” that sarin has been correctly identified. Politico reports that the White House has called for a “comprehensive United Nations investigation.”

More words, then, and weasel words at that. Temporarily, this may just pass muster as fact-checking. But if it turns out that when President Obama lays down red lines and games-changers he doesn’t actually mean it but is only prevaricating, then the position of the United States is compromised, its word becomes meaningless, and its enemies are free to do as they please while its allies are left in the lurch. The warfare certain to break out in such an eventuality will be multiple, bloody, and dangerous.